Preheat the oven to 400. Slice the potatoes about 1/3 inch thick and toss them with a small amount of the olive oil, salt, and pepper. Spread them in a single layer in an ovenproof dish or on a baking sheet (I like to line mine with parchment, to make everything and clean-up, easier) and roast in the oven until they are golden brown and cooked through, about 15 minutes. (Mine took a bit longer.)